Since 1980, a small restaurant in San Francisco’s Cow Hollow neighborhood has thrived on word-of-mouth, despite its location in an alley and its competition from more fashionable restaurants on nearby Union and Chestnut Streets. The Brazen Head had a very small sign on its door, no neon lights and no advertising. Yet, it filled up night after night with locals.

Today, this same phenomenon is repeating itself in neighborhoods throughout the world. Except now, many of these restaurants are underground, i.e., they’re actually rooms in the homes of entrepreneurs and foodies serving high-brow food at low-brow prices.

In Oakland, CA, they’re called the Ghetto Gourmet. In Cuba, the home-based paladares began illegally, but are now real restaurants. In Hong Kong, they’re known as si fang cai or speakeasies. They’re also popular in Paris, Prague and more.